Blind-stitch sewing machine



Nov. 2, 1943. G, STEVENSON 2,333,128

BLIND-STITCH SEWING MACHINE Filed Jan. A31, 1940 3 Sheets-Sheet 1 O @letz-71j L? :I Ao

INVENTOR NOV. 2, 1943. Q STEVENSQN 2,333,128

BLIND-STITCH SEWING MACHINE Filed Jan. si, 1940 :s sheets-sheet 2 f3 @49153. 4| d A O 11 INVENTOR Nov. 2, 1943.

G. STEVENS'ON BLIND-'STITCH SEWING ,MACHINE Filed Jan. 51, 1940 5 sheets-shet s /O V8 i @$5.1 -z

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INVENTQR Patented Nov. 2, 1943 2,333,128 BLIND-STITCH SEWING MACHINE Geoffrey Stevenson,

Lewis Invisible St Brookline, Mass., assignor to itch Machine Company,

St. Louis, Mo., a corporation of Maine Application January 31, 1940, Serial No. 316,484

4 Claims.

The invention herein disclosed relates to blindstitch sewing machines of the type in which workpresenting mechanism is utilized to intermittently present a node of material to the stitch-forming mechanism.

p In machines of this type, particularly the small high speed machines, it has been, prior to this invention, the common practice to mount the work table of the machine such that it is movable toward and away from the plane of the presser foot. The work support for supporting the work against the presser foot is mounted on the work table as is also the work-presenting mechanism. The adjustment of the penetration, and the opening of the machine is effected through this worktable. A heavy, strong spring is utilized to maintain the table rigid in the adjusted position and the adjusting mechanism and the operator must work against this spring in adjusting the penetration and in opening and closing the machine for the insertion and removal of the work.

By this invention, there is provided a blindstitch sewing machine which includes a stationary work-table and in which the penetration adjustment operates against one resilient means and in which the operator Works against only the resilient means of the Work support in opening the machine for the removal and insertion of work. In accordance with the invention, the work-presenting mechanism and the work support are independently,.movably mounted in a stationary `work-table. The arrangement provides adequate room between the presser foot and the retracted work support for the insertion and removal of the work.

A machine embodying the invention is illustrated in the accompanying drawings in which:

Fig. 1 is a plan of the machine partly brokenaway;

Fig. 2 is an end elevation of the same;

Fig. 3 is a front elevation, partly in section;

Fig. 4 is a transverse section taken on the line 4-4 of Fig. 3;

Fig. 5 is a transverse section of the work-table taken on the line 5-5 of Fig. 3;

Fig. 6 is an end section of the work table taken on the line 6-6 of Fig. 1;

Fig. 7 is a partial plan of the work table;

Fig. 8 is a partial longitudinaI section of the work table taken along the line 8 8 of Fig. 6;

Fig. 9 is a partial rear elevation of the work table; and

Fig. 10 is a transverse section taken on the line IU-IU of Fig. 7.

The machine illustrated in the drawings includes (Figs. 1 and 2) a frame that comprises a casting forming a base I upon which the machine is mounted. Another casting, which is secured to the base I includes a standard 2 that extends -from the base, at an angle to the plane of the base, and an arm 3 extending from the upper end of the standard. A casting forms an arm 4 extending from the end of the horizontal arm 3 towards the work table 5. The work table is formed as a casting and it is bolted to the base I.

VThe stitch-forming mechanism is mounted on the end of the forwardly extending arm 4 and it is of the usual construction for machines of this type. This stitch-forming mechanism includes a needle shaft 6 which extends through the forward end of the forwardly extending arm 4. On the end of the needle shaft 6 there is secured a needle bar l which carries a needle 8 that is oscilvklated or reciprocated across an opening through a stationary presser foot 9. The needle shaft 6 is oscillated in the usual manner from the main shaft l0 oi' the machine which extends through the horizontal arm 3 and is'journaled therein. The usual hand wheel II and groove pulley I2 is mounted upon the extended end of the main shaft It. The stitch-forming mechanism of the machine may be either for forming the well-known lock or chain stitch. l

The work table extends horizontally at the front of the machine. This tablel includes an extension 5a which extends to a'point in line with the end of the presser foot. To lthe end of this extension, there is secured` a block II in which the work-supporting andI work-presenting mechanism of the machine is mounted.

The block II (Figs. 6-10) extends directlyrbelow the presser foot 9 and includes two spaced end pieces I2 and I3 secured together and in spaced relation by a bottom piece I4. The block is secured to the end of the work table by machine screws I5. The end piece I3 has a vertical groove It formed therein,\in which groove there is received a bearing block I'I that is slidably mounted within the groove. The bearing block includes tongues I'Ic and IIb, one on each side thereof which are received within complementary slots in the side wall of the groove I6. These tongues and grooves position the bearing block and prevent movement thereof parallel to the plane of the presser foot while permitting sliding movement of the bearing block in a direction towards and away from the presser foot. To the lower end of the bearing block, there is secured a rod I8 which is threaded at its lower end. A spring I9 surrounding the rod I8 acts between the base of rof the gear 22.

the groove in which the block is mounted and the lower end of the bearing block to urge the bearing block upwardly in a direction towards the presser foot. A cover plate extends over the groove I5 in the end wall I3 and limits the upward movement of the bearing block.

Through the rod I8 the position of the bearing block I1 with respect to the presser foot may be changed and adjusted for a purpose that will hereinafter appear. The rod I8 extends through the base of the groove in which the bearing block is mounted and through'an opening in the bottom piece I4 of the block I I. A transverse groove 2I (Figs. 6, 8 and 10) is provided in the end wall I3 and forms a recess in which a gear 22 is received. The gear 22 is internally threaded and engages in threaded engagement with the rod I8, Meshing with the gear 22 (Fig. 8) there is a gear 23 that is secured on the hub 2li of a beveled gear 25. The beveled gear 25 is mounted on a shaft 28 and the hub of the beveled gear andthe hub ofthe-gear 23 are secured for rotation together and with the shaft 26 by a pin 21. The hub 24' of the gear 26 extends through an opening in an extension 28 of the end wall i3, the extension 28 extending parallel to the work table. A lateral or perpendicular, Vdownwardly extending, extension 29 formed .on the end of the extension 28 forms a bearing for a shaft-3Q which extends therethrough. On the end of the shaft 30, there is mounted a beveled gear 3I that meshes with the beveled gear 25. The shaft 38 extends longitudinally of the work table (Fig. 3) and through the far end wall 32 thereof in which itis journalled. On the end of the shaft 30 there is secured -a knurled finger wheel 33 which operates Aagainst a spring detent 34. f

By turning the wheel 83,-through the train of gears just described, the gear 22 (Figs. 6, 8 and l0) is rotated and moves thebearingv block I I either against the action of the spring, away from the presser foot, or permits movement towards the presser foot depending upon the direction in which the knurled wheel 33-is rotated. n this way, the position of thebearing block I'I with respect to the presser -foot v may be adjusted and the bearing blockiixedin any adjusted position with respect to the presser1 foot. It will be noted that the groove 2| in which the gear 22 is received, is wider thanfthe thickness The spring I9, however, normally maintains the gear 22 abutting against the upper wall ofthe recess 2'I. Howevenin-the event of abnormal forces acting upon the bearing block II, the bearing block may -move against the action of the spring I9 away from the presser foot. The amount of -movement,-however, will not be suicient to disengage the gears -22 and 23, as the width of the recess 2I is insufficient to permit these gears to become disengaged upon a downward pressure on thebearing block sufficient to compress the spring I9.

The end of a shaft 35 (Fig. 8) extends through the bearing block I'I, and on the endof the shaft, between the end walls I2 and I3 of the block Il, there is mounted a node-former 36 Figs. 6 to 8). This node-former comprises twov diametrically .opposite blades or node-forming elements. The outer edges of these blades may be of equal distance from the center of the node-former or may vary. If a one to one machine is desired, that is, a machine in which the depth of pene tration of the work is the same for each'suc- Acessive stitch, the blades of the node-former are and 8) illustrated includes two spaced universal joints 3l and 38. Between these universal joints there is a telescopic relation of the shaft. This telescopic relation is effected through a sleeve t0 which' receives the solid shaft. A key 4I, enlgaging in keyways in the shaft and the sleeve,

prevents relative rotational movement of the shaft and sleeve but permits telescopic or longitudinal elongation and contraction of the shaft. In this way, there is `attained a longitudinal expansible and transversely flexible shaft. Some longitudinal Vexpansion and contraction of the shaft is required since the bearing block I'I moves in a fixed path substantially perpendicular to the axis of the shaft. YThetelescopic arrangement described is utilizedto provide this longitudinal expansion and contraction of the shaft. The otherend of the shaft, the end opposite to that on which the node-former is mountedyis journaled in a bearing ft2 provided therefor `in the work table. Y l

Intermediate the universal 38 (Figs. 3 ande) andthe bearing 42, there is mounted on the shaft a helical gear lit. IThis gear i3 meshes with another helical gear secured "on the end of a shaft 25. The shaft 2.8 extends rearwardly kof the machine and at its rearend it is journaled in a bearing block il mounted in the rear wall of the standard 2. Within thestandard 2, there is mounted on the shaft i5 a helical gear 48. This gear meshes with a gear i9 mounted on the main shaft I0 of the machine. Thus, the

-shaft`35 is caused to'rotate with the shaft-I8. I The ratio of the gears i8 and' d8 isY one to one. The ratio of the gears 'F15 and i3 is two to one.

ln consequence, Ythe shaft 35 and the node-former tt'rotate at one-half the speed of the main shaft of the machine. The gears are adjusted on: the

shaft, so that thefnode-formeris operated in timed relation with respect vtol the oscillations of the' needle, a blade of the node-fermer being in node-forming position as the needle crosses the opening through the presser foot.

Work-supporting plattens and 5i (Figs. 6, 7 and 9) are arranged to support the work against the presser foot, there is a platten on eachside of Athe opening through the presser foot and-on each side of the node-former, the node-former and the opening through the presser foot being in the same vertical plane. rThe platten 5IY is ivotally secured by a pivot 52ar to the end of a bracket 53. The bracket 53 is shaped as clearly shown in Fig. 6 and'is pivotallymounted-at its forward end upon e. pivot pinv 54 that extends between the end walls I2 and I3. Anf'airm 55 extends from the bracketl 53 and hasta` threaded opening therethrough, through-which'opening a set screw 56 is threaded. The set screw, engaging the forward end of thebottoin 'wall I4, limits the movement of the platten'gi -towards th presser foot. A On the bracket 53, there is fo"r""` ed a shoulder 5S in which there is secured a threaded pin 59. The pin 59 has threaded thereon a knurled nut press.

60. Between the nut 68 and a recess formed in the bottom wall I4 of the block II, there is a spring BI which acts to move the` bracket 53 in a direction to press the platten 5I againstthe under-surface oi the presser foot. The knurled nut-60 provide an adjustment for adjusting the force with which the spring 6I acts upon the bracket. On the rear end of the bracket 53, there is` formed allug62. This lug has an elongated transverse slot 63 extended therethrough.

The platten 5E) ismounted on a similar bracket 64 that is also pivotallymounted on `the pivot pin 54,.. A .spring65 acts upon the bracket 64 to urge the bracket in a direction to effect engagement of the platten 50 and the presser foot.

The bracket 64 likewise includes a lug 6B having an elongated slot 61 therethrough. These brackets are independently movable towards the presser foot and the plattens are independently mounted so that they may move freely and independently in accordance with variations in thickness of the work passing through the machine.

To open the machine for the insertion or the removal of work, the plattens are withdrawn against the action of the springs 6I and 65. To this end, a pin 68 extends between and is received in the elongated slots in the lugs on the brackets. These elongated slots permit movement of the brackets relative to the pin and thus permit independent movement of the plattens. Between the brackets, there is secured to the pin a link 69 through which the pin 68 extends. The opposite end of the link 69 is pivotally secured by a pivot screw 10 to the end of a crank 1I. The crank 1I is mounted upon a shaft 12 that is journaled in the wall I3 of the block II and that extends longitudinally of the work table. It is journaled at its opposite end (Fig. 5) in the bearing block 42. The shaft 12 extends through the end of the work table and has mounted thereon (Fig. 3) a lever 13 through which the shaft may be rotated. Within the work table and adjacent the inner end of the bearing block 42 (Figs. 3 and 5) another lever 14 is mounted upon the shaft 12. To the end of the lever 14, there is secured one end of a link or chain 15. The other end of the link 15 is secured to a lever 'I5 mounted upon a forwardly extending shaft 11 journaled in a bearing block 18 formed in the work table. The shaft 11 extends forwardly of the machine and on its forward end it is provided with a sleeve 19 to which the shaft 80 of a knee press (not shown) may be secured.

Thus, the shaft 12 may be rotated either through the lever 13 by hand or through a knee Upon rotation of the shaft 12 in a'direction towards the rear of the machine, counterclockwise as seen in Fig. 10, the link 69 is moved to cause the pin 68 to engage the lower ends of the slots in the lugs B2 and 68. Forward movement of the shaft 1I draws the plattens away from the presser foot. In this way, the plattens may be drawn or retracted until the platten 5| engages the bearing block I1. This provides an adequate opening for the insertion and removal of work in the machine.

In the machine illustrated, the node-former rotates continuously in the direction of the movement of the work through the machine. The position of the bearing block is adjusted through the nger nut 33, for the particular thickness of the cloth being sewn, so that the blades of the node-former project a node of the material through the opening in the presser foot and into the path of the needle. The node-former is timed so that these `nodes in the material are formed and presented as the needle makes its forward or penetrating stroke.v When the needle is fully Withdrawn, the node-former-blades lie parallel to therplane of the presser foot and so allow the maximum space for opening the machine for the removal or insertion of work. It `will be apparent, of course, that the number` of blades in the node-former may be varied for particular situationswith a corresponding variation in the ratio ofthe node-former shaft and the `main shaft. Likewise, the length of the node-former blades' may vary to effect the different relations of successive stitches.

From the foregoing description of the embodiment of the invention illustrated in the drawings, it will be seen that by this invention, Vthere is provided a blind-stitch sewing machine which is greatly simplied in construction and in which the only force that the operator has to work against in order to open the machine is the force of the springs urging the plattens into the contact with the presser foot. 'I'hese are very light springs in comparison to that utilized to hold a movable work table rigid. A stationary, rigid,

Work table is provided and a simple adjustment its relation to the presser foot or the path of the needle. In the event a heavy seam or several thicknesses of cloth passes through the machine, the spring I9 permits the node-former to retract so that the added thicknesses of material is acoommodated.

It will be obvious that various changes may be made by those skilled in the art in the details of the embodiment of the invention illustrated in the drawings and described above within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a blind-stitch sewing machine of the kind described, the combination comprising a presser foot having an opening therethrough, stitchforming mechanism on one side of the presser foot, a stationary Work table, work-presenting mechanism on the other side of the presser foot for presenting work to the stitch-forming mechanism including a rotatable node-former mounted on the work table, a resilient mounting therefor arranged to permit movement of the node-former perpendicular to the plane of the presser foot, and means for operating the node-former.

2. In a blind-stitch sewing machine of the kind described, the combination comprising a substantially horizontally disposed presser foot having an opening therethrough, stitch-forming mechanism on one side of the presser foot, Work-presenting mechanism for presenting work to the stitchforming mechanism including an angularly movable node-former, a resilient mounting therefor arranged to permit movement of the node-former perpendicular to the plane of the presser foot, means for operating the node-former, a worksupport for supporting the work against the presser foot mounted for movement away from the presser foot independently of the nodeformer and suiciently for the insertion and removal of work.

3. In a blind-stitch sewing machine of the type described, the combination comprising a presser foot having an opening therethrough, stitchforming mechanism on one side of the presser foot, work-presenting mechanism on the other side of the presser foot for presenting the work to the stitch-forming mechanism including an mechanism on one side of the presser' foot, Workpresenting mechanism for presenting Work to the stitch-forming'meohanism including an angularly movable nodeformer, a resilient mounting therefori. arranged to permit movement of the nodeformer toward and .away from the presser foot, means for operating the node-former,V a Work support forsupporting the Work against the presser foot` mounted for movement away from the presser foot independently of the nodefo'rmer, and meansA for moving thework support `independently of the node-former'.

GEOFFREY STEVENSON. 

